Based on hitherto overlooked archival material, this book reveals Nell Walden's significant impact on the Sturm organisation through a feminist reading of supportive labour that highlights the centrality of collaborative work within the modern art world. This book introduces Walden as an ardent collector of modern and indigenous art and critically contextualises her own art production in relation to expressionist concepts of art and to gendered ideas on abstraction and decoration. Visual analyses highlight how she collaborated with professional and experimental women photographers during the Weimar era and how the circulation of these photographs served as a means to intervene in the public sphere of culture in interwar Germany. Finally, the book provides an analysis of Walden's continuing work for Der Sturm after her voluntary exile from Germany to Switzerland in 1933 and highlights the importance of women's supportive labour for the canonisation and institutionalisation of modern art in museums and archives. The book will be of interest to scholars working in art history, visual studies, and gender studies.